ASP.NET Core MVC Enforce SEO 2021 - asp.net-core

Question

Everyone needs to do common SEO rules, but there is no widely published way in ASP.NET Core MVC to:
Redirect http to https
Redirect non-www to www
Rewrite URLs as lower case
Remove trailing /
In ASP.NET these were rewrite rules in web.config. The common answer is adding the following in Startup.cs which doesn't enforce or rewrite:
services.AddRouting(options => options.LowercaseUrls = true);
services.AddRouting(options => options.AppendTrailingSlash = true);
I think the best way is adding middleware with the app.Use, but I can't find a proven example. Here's my Startup.CS:
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
namespace Matrixforce
{
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddControllersWithViews();
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
app.UseExceptionHandler("/Error");
// The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
app.UseHsts();
}
// CUSTOM redirect to 404 page not found
app.Use(async (context, next) =>
{
await next();
if (context.Response.StatusCode == 404)
{
context.Request.Path = "/404/";
await next();
}
});
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Index}/{id?}");
});
}
}
}

Answer 1

Vitali Karmanov on Github has a good example of requirements 3 and 4 but NOT 1 and 2. Now I just need an example of the first two rules to add to the custom Helper.
/Helpers/RedirectLowerCaseRule.cs
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Rewrite;
using Microsoft.Net.Http.Headers;
using System.Linq;
using System.Net;
namespace Matrixforce.Helpers
{
public class RedirectLowerCaseRule : IRule
{
public int StatusCode { get; } = (int)HttpStatusCode.MovedPermanently;
public void ApplyRule(RewriteContext context)
{
HttpRequest request = context.HttpContext.Request;
PathString path = context.HttpContext.Request.Path;
PathString pathbase = context.HttpContext.Request.PathBase;
HostString host = context.HttpContext.Request.Host;
if ((path.HasValue && path.Value.Any(char.IsUpper)) || (host.HasValue && host.Value.Any(char.IsUpper)) || (pathbase.HasValue && pathbase.Value.Any(char.IsUpper)))
{
HttpResponse response = context.HttpContext.Response;
response.StatusCode = StatusCode;
response.Headers[HeaderNames.Location] = (request.Scheme + "://" + host.Value + request.PathBase + request.Path).ToLower() + request.QueryString;
context.Result = RuleResult.EndResponse;
}
else
{
context.Result = RuleResult.ContinueRules;
}
}
}
public class RedirectEndingSlashCaseRule : IRule
{
public int StatusCode { get; } = (int)HttpStatusCode.MovedPermanently;
public void ApplyRule(RewriteContext context)
{
HttpRequest request = context.HttpContext.Request;
HostString host = context.HttpContext.Request.Host;
string path = request.Path.ToString();
if (path.Length > 1 && path.EndsWith("/"))
{
request.Path = path.Remove(path.Length - 1, 1);
HttpResponse response = context.HttpContext.Response;
response.StatusCode = StatusCode;
response.Headers[HeaderNames.Location] = (request.Scheme + "://" + host.Value + request.PathBase + request.Path).ToLower() + request.QueryString;
context.Result = RuleResult.EndResponse;
}
else
{
context.Result = RuleResult.ContinueRules;
}
}
}
}
Startup.cs
using Matrixforce.Helpers;
app.UseRewriter(new RewriteOptions().Add(new RedirectLowerCaseRule()).Add(new RedirectEndingSlashCaseRule()));